Introduction
In earlier chapters, we learned about templates that are used to create functions and classes that work with arbitrary types. This avoids duplication of work. However, using templates is not applicable in all cases, or may not be the best approach. The limitation of templates is that their types need to be known when the code is compiled.
In real-world cases, this is not always possible. A typical example would be a program that determines what logging infrastructure to use depending on the value of a configuration file.
Consider the following problems:
While developing the application and executing tests, the application would use a logger that prints detailed information.
On the other hand, when the application is deployed to the PCs of its users, the application would use a logger that prints error summaries and notifies the developers if there are any errors.
We can solve these problems using the concept of inheritance in C++.
